BeoMaster 2400-2 Volume controle

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Hello.

Does anyone have a schematic over a BeoMaster 2400-2 ?
It is the volume control I am interested in.
And if some one could email it to me I would be happy.

It has the problem that when you touch the volume up touch panel, it will go to MAX output.

Thx.

Best regards Thias Russell
 
Hi guys, repaired a lot of those some years back in my old job. Sometimes you just need to clean (spray) the carbon tracks of the potentiometer, but increasingly the later years, the potmeters were broke, meaning the connections between the carbon tracks and the solder pins had died. Just an info. Good luck with the repairs 🙂
 
I have Beomaster from my friend on my table. I try to repair that amp for a few days.
It was not working ok...bulbs were dead and volume was not responsive and it was just heard distorded sound on phones-speakers.
I changed all capacitors and replaced all bulbs with new one. BUT ...original bulbs are 15V-1W i have used 14V..50mA!!! so i put 220R across each bulb.
After start up all bulbs are ok all is working, but from phones just little little signal ...amp is in MUTE!
volume touch is responding, so goes up and down, but no sound on phones-speakers.
Here are 2 pictures
So problem is with MUTE.... -12V is present all the time instead 0V on mute fets.
ILUFAULT voltage is not right so LDR is not working... LDR is working ok, because when in accidentaly disconnected +15v supply on control board volume bulb glows at full position an touch was not responding but sound was at max position and i almost damaged earphones because of loud signal.
Ldr control is also working ...i measured voltage ..it goes form 6..7V till 12..13V on emitter of TR23 but not on tr24 that drives ldr...because of not right FAULT voltage?
I read that problems can be made because of bulbs...they not have enough current consumption and not give enough voltage drop on resistor 33R. It was true..without resistor i get 0.8V voltage drop ...now with 220R over each bulb it is 2,5V.
Is it too small???...if you check shematics.
because FAULTIL transistor TR6 is not opened and -12v goes on to the Muting transistors trought 1M resistor
I checked with scope ...and audio signal comes till mutting transistors and there shut down.Also checked modulation frequency on control board- level..ok
Thank you for any help.
 

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